This invention relates to a magnetophoretic display panel. Magnetophoretic display panels are known which comprise a plurality of cells sandwiched between two substrates and each of which is filled with a liquid dispersion that comprises magnetic particles, a dispersion medium, a colorant and, optionally, a thickener. When a magnetic pen is moved along the substrate on the front side, the magnetic particles are attracted by magnetic force of the pen and move from the substrate on the back side to produce a difference in contrast between the color of the liquid dispersion and that of the magnetic particles. This contrast is sufficient to create a display. Such is described in U.S. Pat. No. 4,143,472.
Such conventional magnetophoretic display panels have the problem that, depending on the type of magnetic particles, whiskers appear at the edge of the line of the image produced by movement of the magnetic pen. Thus, the line width becomes unseen along its length. This phenomenon is shown enlarged in FIG. 1. Element 2 is an image line having whiskers 1 at its edge. Element 4 is a cell held between the substrates. In contrast, FIG. 2 shows an image line 3 that has a uniform width in the absence of whiskers. This is the desired line configuration. In both FIGS. 1 and 2, the direction of movement of the magnetic pen is indicated by the arrow.